HVAC Library

Home Fuel Source Cost Comparison
Home-heating costs range widely with the fuel source, and the cost of each fuel varies from region to region.

When talking to your heating contractor, be sure you know both the local fuel costs and the efficiency of the heating unit you plan to install.

To help you determine what is best for you, consider the following (BTU stands for British Thermal Unit, a standard for measuring heat output):

Natural gas burns 10 therms to produce 1 million BTUs.
Electricity uses 293 kilowatt hours to produce 1 million BTUs.
Propane burns 10.9 gallons to produce 1 million BTUs.
Heating oil burns 7.21 gallons to produce 1 million BTUs.

The cost of each of these fuels varies widely across the nation. For instance, imagine if 293 kilowatt hours of electricity in New England costs $100, but 10.9 gallons of propane only costs $40. In this case, it would cost half as much to heat with propane. But the same amount of electricity might cost $30 in the Pacific Northwest, making electricity the less expensive alternative.

In order to know which fuel is most economical for you, we suggest you sit down with your contractor and discuss the efficiency of your heating unit and the regional cost of the fuel it will use. Together you can determine the best product for your home.

Controlling Your Home's Humidity
Lack of humidity in a home can be the cause of numerous respiratory ailments. Fortunately, there is a way to improve humidity levels within the home.

Your home’s humidity level should be between 30 to 60 percent. Too much humidity can promote the growth of mold; too little humidity can dry out your body's mucus membranes, causing a variety of ailments. During extremely cold weather, a home loses humidity to the outdoors and the level may drop to as low as 10 percent

Whole-house humidifiers put moisture into the air, making harsh, dry air easier to breathe. Most humidifiers use from 1.5 to 12 gallons of water per day—just enough to raise the humidity to the desired level, but not enough to make a difference on the water bill. And because a humidifier is installed in the ductwork, there is no need to carry one from room to room or remember to fill it with water.

There are many factors to take into consideration when selecting a humidifier, so it is best to speak with a qualified HVAC contractor to determine which option best meets your needs.

Illness and Your Home's Ductwork
Although flexible metal HVAC ductwork can distribute indoor dust and other contaminants, its greater threat is that it may also be a breeding ground for mold growth.

If indoor humidity levels are above normal (above 40% humidity) or condensation forms due to thermal bridging (heat loss through the non-insulated portions of your home), moisture can become trapped in flex duct grooves or insulated ductwork panels, allowing mold to flourish. Public Health centers identify mold as a leading cause of “sick-house” syndrome, which causes headaches, asthma, and other health problems.

Generally, cleaning alone will not eliminate mold from a HVAC system, since power vacuuming cannot dislodge molds forming in deep crevasses. An inspection by a qualified HVAC technician may be necessary to check for serious problem areas.

Baseboard Heaters and Child Safety
Although electric baseboard heat is an economical way to heat individual rooms, it has some drawbacks, especially when it comes to safety and children.

Baseboard heaters are low to the floor and easily accessible to babies and toddlers. The hot surface could cause burns—and blankets, stuffed animals, and clothing laid against baseboard heaters could ignite. The Mayo Clinic suggests putting a screen or barricade around them in the winter months, but for most people, this is an impractical solution.

If you have children, you may want to talk to a qualified heating specialist about other options for your home.

A Simple Way to Determine If You Need a New Furnace
The best time to buy a new furnace is before it breaks down. This gives you the chance to shop around in comfort, rather than rushing to get the heat back on.

If your system already has broken down and the repair costs exceed $500, the better investment is to replace rather than repair.

The typical furnace has a life-expectancy of 16–20 years, so if your current system is over ten years old, it may be time to start looking at your options.

An old furnace, even if it is working well, may be extracting only 60% of the available heat from the fuel used to heat your house. Newer fuel-efficient heating systems use as much as 90% of the heat available in the fuel. If you’re looking to lower your fuel bills, now is the time to consult a HVAC contractor and discuss your options.

Learn what the different thermostat wiring colors mean

and how to service and repair control wiring.

On your gas furnace, oil burner, heat-pump or air-conditioner.

I get many inquiries about what the different wire colors mean and what they do and how troubleshoot problems where nothing happens or some parts will work and others will not.

First I am not into disclaimers because I assume you are smart enough to know not to mess with stuff that you are not familiar with or competent at doing. However I must make an exception here.

Control wiring on hvac equipment while harmless looking and 24 volts ac wont shock you (it will bite) can cause very bad things to happen if connected incorrectly. You could destroy your equipment at best or burn down your home or business at worst. Among the control wiring can be high voltages from 120/240 volts in a residential furnace to 480 or 600 volts in commercial equipment that can kill you instantly or burn you in a flash.

So if you are unsure of what you are doing or your abilities please leave it to someone who understands control wiring and electricity. If you need to ask for a wiring diagram then it is a good bet that you should seek extra help because the knowledge required to do the job safely far exceeds the knowledge required to read a diagram. So if you are having trouble with wiring to the point where you think that you need a diagram then its doubtful that one would help you.

Keep in mind that more than one disconnect may be required to remove all power from a piece of equipment. If your unit has service switches find them first. Or turn off the circuit breakers or pull the fuses, then check with a meter or test lamp to be sure the circuit is dead.

With all that said lets get to the terminal designations and colors. These designations are for 24 volt control wiring used in most residential and light commercial equipment, line voltage stuff can be different. Never assume that a wire color is correct for the function it should perform; check it out first The same goes for high voltage control wiring and motor terminals .

{Terminal name}, {color}, {function}
(R), Red, hot side of transformer.
(C) Common side of transformer (See B)
(Y), Yellow, Compressor activity (cooling or cooling and heating on a heat pump).
(W), White, Heat (gas burner, oil burner , electric heat, (auxiliary heat on a heat pump including defrost output from the outdoor unit to activate electric heat and turn on the AUX. heat lamp).
(G), Green, furnace blower fan. (needed for air conditioning, heat pumps and some electric furnaces). NOTE: on most thermostats the "G" and "Y" are connected together at all times when the fan switch is in the "Auto" mode, If you sully R to G then you will most likely energize the outdoor unit contactor!
(O), Orange , Energize to cool (used for reversing valve on heat pumps)
(B), Blue or Orange, Energize to heat (used on some systems, Rheem/Ruud is notorious for this).
(B) or (X), Blue, brown or Black, common side of transformer. Needed on some electronic thermostats or if you have indicator lamps. Do not confuse with (B) Reversing valve (energize to heat) above. York and Trane like to use (B) as common.
(E), blue, pink, gray or tan, emergency heat relay on a heat pump. Active all the time when selected, usually not used.
(T), Tan or Gray, outdoor anticipator reset.
Used on GE/Trane/American Standard and some Carrier Products.
(W2), Pink or other color, second stage of heat (may be same as (W) on heat pump or fossil fuel system). Note: some thermostats require a jumper from W1 to Y for heat pump operation.
(Y2), Blue or Pink, second compressor stage.
(L), Blue, brown, tan or gray service indicator lamp.
Numbers, see manufacture's diagrams but can be stages of electric heat especially on York/Borg Warner/Coleman-Evcon, Frasier Johnson/ Air-pro.
(X2), Second stage of Electric Heat on GE/Trane/American Standard. See link above. Also used as indicator lamp or misc. contacts on other systems.
Learn more about a Heat Pump Thermostat.

Warning: Do not confuse "B" Common (York and Trane)!
With "B" Energize reversing valve to heat (Rheem/Ruud/Weatherking)!

1819 light bulbs and sockets avaliable from Radio Shack

If you need to see the 24 volt control signal this lamp is an easy way do it. This 1819 lamp and sockets are available from Radio Shack. This clamp on ac ammeter is valuable for measuring ac current. The built in "Non Contact Volts" feature is worth the price. About $80 at Lowes or The Home Depot.

I cannot say it enough times: You should never go after your thermostat as a cause of the problem until you verify with test lamps or a meter. To do so you are not solving the problem but creating more and risk blowing a fuse or the control transformer. On most systems you can get to the control wiring at the air handler or furnace and take your reading there. You should only replace or change a thermostat after you verify that it does have a problem.

If your system does not have a fuse protecting the secondary side of the transformer add one before proceeding! An automotive ATC fuse holder and a 3 amp fuse should do the job. If you have a GE, Trane or American Standard unit and you blow the control fuse that is proprietary, replace it with and automotive 3 amp ATC fuse.

Link to White Rodgers that has a good look up table of different manufacturers. You will notice that Lennox's color codes are TOTALLY WEIRD to put it gently.
Link to White Rodgers Clip art that has pictures of their different control products.

I would highly suggest identifying each wire by connecting the hot lead to each function wire with clip leads and a 3 amp fuse and recording the function before installing your new thermostat. While this is more trouble it may save you from ruining your day.